(a) It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both): I heard the Messenger of Allah (peace and blessings be upon him) saying: "When anyone intends to come to the Friday prayer, let him take a ritual bath."
(b) Sayyiduna Ibn Umar (may Allah be pleased with them both) said: The ritual bath is only upon the one for whom the Friday prayer is obligatory. It is also reported from him that he did not take the ritual bath on Friday while travelling. (c) Some others besides him held that one should take a ritual bath once every week for the sake of cleanliness.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 1419